There is a need for an efficient device for accepting or rejecting, by weight, similar articles that are delivered to a weighing device. In particular, there is a need for a system for checkweighing similar articles and containers which are to meet specified weight criteria, and separating, at the point of weighing, those that meet the criteria from those which do not.
A 1914 patent to Sloan and Barnes, U.S. Pat. No. 1,089,680, describes a weighing system for quality control of cigarettes based on weight, wherein the rate of manufacture is regulated according to whether the cigarettes are within specification. Drums are rotated for filling and discharge according to the weight of their contents, in Vogel-Jorgensen""s U.S. Pat. No. 2,055,131.
A simple platform on a load cell is proposed by Lumby et al for weighing fowl, in U.S. Pat, No. 3,780,818. Mims, in U.S. Pat. No. 4,155,549, sorts heavier and lighter balls by combining a diverting plate with a pivotable weighing plate. A hopper is actuated by Okada for releasing objects heavier than a preset value, in U.S. Pat. No. 5,611,437. And, Shaanan et al, in U.S. Pat, No. 5,708,236, describe a cantilever beam for transmitting force, i.e. weight, to a strain gauge.
It is not uncommon to employ a weigh station in a production conveying line for determining whether the produced items are too heavy or too light, wherein the system automatically diverts an out-of-specification item from the conveying line at a point downstream from the weigh station. The actual weighing can take place as the item is moving or in a static condition, but in either case the diversion or separation typically is conducted at a point further removed from the weigh station. See, for example, Kvisgaard et al U.S. Pat, No. 5,998,740, Tokutu U.S. Pat, No. 5,383,561, Beauchemin et al U.S. Pat, No. 5,006,225, Rice et al U.S. Pat, No. 3,139,184, and Altenpohl et al U.S. Pat. No. 3,596,749.
I am not aware, however, of a system of the type described below, wherein an object is weighed on a weigh platform which itself is tilted immediately to divert the object when it is too heavy or too light.
My invention is useful in production lines, particularly those having a conveying system and wherein weight specifications are important. It is a checkweighing system wherein a newly produced or other item is placed, as by a robot arm, on a weigh platform, the item is weighed, and, if it is outside a desired weight range, the platform is tilted to cause the item to slide or fall into a bin or onto a diverting conveyor. My invention is quite versatile, in that the weigh interval or time, the speed of the tilt, and the degree of the tilt can be readily adjusted. My system will not only accept or reject the production items one at a time, but can discern trends and be used otherwise to adjust production practices.